[JavaSpring] Bug generating @Pattern regex

[elier]

Description

When generating from this yaml file:
https://raw.githubusercontent.com/OpenBankingUK/account-info-api-spec/master/dist/v2.0.0/account-info-swagger.yaml

Regex pattern like this '^\d{1,13}.\d{1,5}$' are not escape property and the generated java code does not compile.

To discuss: Should the code generation be responsible for escaping the regex properly for every language? or Should I modify the YAML to provide the appropriated escape?

Swagger-codegen version

3.0.8

Swagger declaration file content or url

definitions:
  Amount:
    type: string
    pattern: '^\d{1,13}\.\d{1,5}$'

Command line used for generation

swagger-codegen generate -i https://raw.githubusercontent.com/OpenBankingUK/account-info-api-spec/master/dist/v2.0.0/account-info-swagger.yaml -l spring -o api-server

Steps to reproduce

swagger-codegen generate -i https://raw.githubusercontent.com/OpenBankingUK/account-info-api-spec/master/dist/v2.0.0/account-info-swagger.yaml -l spring -o api-account
mvn install

Related issues/PRs

Suggest a fix/enhancement

Wrong java code generated:

@Pattern(regexp="^\d{1,13}\.\d{1,5}$")   

Right code generated should be: \

@Pattern(regexp="^\\d{1,13}\\.\\d{1,5}$")   

[erreobi]

I'm having the same problem now ... we have just updated to the version from 2.3.1 to 2.4.5

[shameerkc]

Facing the same issue, while working with https://github.com/jdegre/5GC_APIs/raw/master/TS29571_CommonData.yaml

    Mnc:
      type: string
      pattern: '^\d{2,3}$'
`

Generated output includes below error: java: **illegal escape character**


```java
@Pattern(regexp="^\d{2,3}$")   public String getMnc() {
    return mnc;
  }

`

[markwoon]

Still a problem with 3.0.21

[volkerrichert]

and also in 3.0.23. This is open since nearly 2 years. Does anyone have a workaround?

[HugoMario]

Hi @volkerrichert ,

Yes, we're working on this, and any PR is always welcome

[msm416]

Hello @HugoMario,

I've run into the same problem (single forward slash instead of double, for my regex) while invoking the 3.0.24 jar on my own spec, but for jaxrs-jersey

What is the progress on this issue for both spring and jaxrs-jersey?

Thank you!

[cdprete]

I can confirm the same issue for version 2.4.19

[cdprete]

Weird enough, if you provide an example in the definition then the pattern is correctly generated, unless you reference a scalar type with $ref. In such a case, the pattern is copied over without the example and it's then broken again...

[ambition-consulting]

still applies in 4.3.1 when converting @digits(integer = Integer.MAX_VALUE, fraction = 3) to @pattern(regexp="^\d{1,2147483647}([.]\d{1,3})?$")

[dlhermit]

Is there any progress on this issue?
We are currently using the last version, and the bug is still there

<groupId>io.swagger.codegen.v3</groupId>
<artifactId>swagger-codegen-maven-plugin</artifactId>
<version>3.0.36</version>

As a workaround we are using

<groupId>org.openapitools</groupId>
<artifactId>openapi-generator-maven-plugin</artifactId>
<version>6.2.1</version>

This one gegerates the correct code